Role and Clinical Utility of Cancer/Testis Antigens in Head and Neck Squamous Cell Carcinoma

Cancer/testis (CT) antigens exhibit selective expression predominantly in immunoprivileged tissues in non-pathological contexts but are aberrantly expressed in diverse cancers. Due to their expression pattern, they have historically been attractive targets for immunotherapies. A growing number of studies implicate CT antigens in almost all hallmarks of cancer, suggesting that they may act as cancer drivers. CT antigens are expressed in head and neck squamous cell carcinomas. However, their role in the pathogenesis of these cancers remains poorly studied. Given that CT antigens hold intriguing potential as therapeutic targets and as biomarkers for prognosis and that they can provide novel insights into oncogenic mechanisms, their further study in the context of head and squamous cell carcinoma is warranted.

Role and Clinical Utility of Cancer/Testis Antigens in Head and Neck Squamous Cell Carcinoma

Cancer/testis (CT) antigens exhibit selective expression predominantly in immunoprivileged tissues in non-pathological contexts but are aberrantly expressed in diverse cancers. Because of their expression pattern, they have historically been attractive targets for immunotherapies. The investigation of mechanistic roles of CT antigens in promoting oncogenesis has historically been a prominent research question, and a growing number of studies implicate CT antigens in promoting almost all the hallmarks of cancer. This suggests that CT antigens may act as cancer drivers. CT antigens are expressed in head and neck squamous cell carcinomas, although their role in the pathogenesis, prognostication, and treatment for this family of cancers remains poorly studied. Given that CT antigens hold intriguing potential as therapeutic targets and as biomarkers for prognosis and therapeutic response and that they can provide novel insights into oncogenic mechanisms, their further study in the context of head and squamous cell carcinoma is warranted.

MONTE enables serial immunopeptidome, ubiquitylome, proteome, phosphoproteome, acetylome analyses of sample-limited tissues

Multiomic characterization of patient tissues provides insights into the function of different biological pathways in the context of disease. Much work has been done to serialize proteome and post-translational modification (PTM) analyses to conserve precious patient samples. However, characterizing clinically relevant tissues with multi-ome workflows that have distinct sample processing requirements remains challenging. To overcome the obstacles of combining enrichment workflows that have unique input amounts and utilize both label free and chemical labeling strategies, we developed a highly-sensitive multi-omic networked tissue enrichment (MONTE) workflow for the full analysis of HLA-I and HLA-II immunopeptidome, ubiquitylome, proteome, phosphoproteome and acetylome all from the same tissue sample. The MONTE workflow enables identification of a median of 9,000 HLA-I peptides, 6,000 HLA-II peptides, 10,000 Ub sites, 12,000 proteins, 20,000 phosphorylation sites and 15,000 acetylation sites from patient LUAD tumors. Because all omes are generated from the exact same tissue sample, there is less biological variability in the data enabling more robust integration. The information available in MONTE datasets facilitates the identification of putative immunotherapeutic targets, such as CT antigens and neoantigens presented by HLA complexes, as well as reveal insights into how disease-specific changes in protein expression, protein degradation, cell signaling, metabolic, and epigenetic pathways are involved in disease pathology and treatment.

Cancer Testis Antigen, NOL4, Is an Immunogenic Antigen Specifically Expressed in Small-Cell Lung Cancer

To identify cancer/testis (CT) antigens and immunogenic proteins, immunoscreening of testicular and small-cell lung cancer cell line NCI-H889 cDNA libraries was performed using serum obtained from a small-cell lung cancer (SCLC) patient. We obtained 113 positive cDNA clones comprised of 74 different genes, designated KP-SCLC-1 through KP-SCLC-74. Of these genes, 59 genes were found to be related to cancers by EMBASE analysis. Three of these antigens, including KP-SCLC-29 (NOL4), KP-SCLC-59 (CCDC83), and KP-SCLC-69 (KIF20B), were CT antigens. RT-PCR and western blot analysis showed that NOL4 was frequently present in small-cell lung cancer cell lines (8/9, 8/9). In addition, NOL4 mRNA was weakly, or at a low frequency, or not detected in various cancer cell lines. Our results reveal that NOL4 was expressed at protein levels in small-cell lung cancer tissues (10/10) but not detected in lung adenocarcinoma and squamous cell carcinoma by immunohistochemical analysis. Serological response to NOL4 was also evaluated by western blot assay using NOL4 recombinant protein. A humoral response against NOL4 proteins was detected in 75% (33/44) of small-cell lung cancer patients and in 65% (13/20) of healthy donors by a serological western blot assay. These data suggest that NOL4 is a specific target that may be useful for diagnosis and immunotherapy in SCLC.

Immunohistochemical Detection of Cancer-Testis Antigen PRAME

Cancer-testis (CT) antigens were identified by their ability to elicit T- or B-cell immune responses in the autologous host. They are typically expressed in a wide variety of neoplasms and in normal adult tissues are restricted to testicular germ cells. PReferentially expressed Antigen of Melanoma (PRAME) is a member of the family of nonclassical CT antigens being expressed in a few other normal tissues besides testis. Interestingly, knowledge about the protein expression of many CT antigens is still incomplete due to the limited availability of reagents for their immunohistochemical detection. Here, we tested several commercially available serological reagents and identified a monoclonal antibody suitable for the immunohistochemical detection of PRAME in formalin-fixed paraffin-embedded specimens. We also tested a wide array of normal and neoplastic tissues. PRAME protein expression in normal tissues is congruent with original molecular data being present in the testis, and at low levels in the endometrium, adrenal cortex, and adult as well as fetal ovary. In tumors, there is diffuse PRAME immunoreactivity in most metastatic melanomas, myxoid liposarcomas, and synovial sarcomas. Other neoplasms such as seminomas and carcinomas of various origins including endometrial, serous ovarian, mammary ductal, lung, and renal showed an intermediate proportion of cases and variable extent of tumor cells positive for PRAME protein expression. As seen with other CT antigens, hepatocellular and colorectal carcinoma, Leydig cell tumors, mesothelioma, and leiomyosarcoma are poor expressers of PRAME.

Personalized neoantigen/cancer testis antigen nanovaccine (PVAC) mobilize specific therapeutic immunity for high-risk resected gastric cancer.

4535 Background: 35% of stage IIIB/C Gastric cancer patients will recurrent after D2 gastrectomy within one year. Mutation-derived epitopes (neoantigens) has been demonstrated to induce tumor cell specific immune responses controlling the tumor growth. Nanovaccine can increase antigen presentation efficiency and elicit potent antitumor T cell responses with robust therapeutic efficacy. We hypothesized that vaccination with neoantigens/cancer testis (CT) antigens could expand pre-existing and induce antigen-specific T-cells populations, favouring of tumor control enhancement. Here, we report the first-in-human application of this concept in gastric cancer. Methods: Patient-specific mutation-containing neoantigens were selected on the basis of tumour-specific mutations whole-exome sequencing (WES) and RNA sequencing. Cancer testis antigens were obtained according to immunohistochemical staining and HLA-binding affinity prediction. PVAC is an amphiphiles nanovaccine loaded with multiple personalized neoantigens/cancer testis antigens designed to induce antigen specific T cells and associated antitumor responses. PVAC will be administrated to stage IIIB/IIIC gastric carcinoma after six cycles of adjuvant chemotherapy (S-1/Oxaliplatin or S-1/docetaxel). Each patient received PVAC by subcutaneous injection on Days 1, 4, 8, 15, 22, 43, 64, 85, 169, administrated with the adjuvant montanide ISA 51 VG. Safety, immunogenicity and clinical efficacy will be evaluated. Results: 25 stage IIIB or IIIC gastric cancer patients were enrolled in this study. Mean age was 54.3 years old (range: 34-70), and ECOG performance scores were 0 or 1. Repeated dosing has been well tolerated with mild local discomfort and no DLTs. Three patients were observed grade 2 local skin reactions in the injection sites. No SAEs related to PVAC have been observed. Among median follow up time of 12.6 months (range: 8.5-25.0 months), only two patients had local recurrence at 24.0 months and 10.5 months after surgery, respectivelt. The rest 23 patients remain disease free on study. Neoantigen specific T cell responses have been detected by IFN-γ Elispot from PBMCs. Conclusions: PVAC is a multiple neoantigen/CT antigens nanovaccine that personalizes tumor specific antigens and the individual patient’s capacity to respond. Addition of PVAC may prolong progression-free survival (PFS) after the standard of care chemotherapy. Clinical trial information: ChiCTR1800017319 .

MAGE-A4, NY-ESO-1 and SAGE mRNA expression rates and co-expression relationships in solid tumours

Background: Cancer testis (CT) antigens are promising targets for cancer immunotherapies such as cancer vaccines and genetically modified adoptive T cell therapy. In this study, we evaluated the expression of three CT antigens, melanoma-associated antigen A4 (MAGE-A4), New York oesophageal squamous cell carcinoma 1 (NY-ESO-1) and sarcoma antigen gene (SAGE). Methods: MAGE-A4, NY-ESO-1 and/or SAGE antigen expression in tumour samples was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Informed consent was obtained from individuals prior to study enrolment. Results: In total, 585 samples in 21 tumour types were evaluated between June 2009 and March 2018. The positive expression rates of these CT antigens were as follows: MAGE-A4, 34.6% (range, 30.7-38.7); NY-ESO-1, 21.0% (range, 17.2-25.1); and SAGE, 21.8% (range, 18.5-25.4). The MAGE-A4 antigen was expressed in 54.9% of oesophageal cancers, 37.5% of head and neck cancers, 35.0% of gastric cancers and 34.2% of ovarian cancers; the NY-ESO-1 antigen was expressed in 28.6% of lung cancers, 25.3% of oesophageal cancers and 22.6% of ovarian cancers; and the SAGE antigen was expressed in 35.3% of prostate cancers, 32.9% of oesophageal cancers and 26.3% of ovarian cancers. The most common tumour type in this study was oesophageal cancer. MAGE-A4, NY-ESO-1 and SAGE antigen expression were assessed in 214 oesophageal cancer samples, among which 24 (11.2%) were triple-positive, 58 (27.1%) were positive for any two, 59 (27.6%) were positive for any one, and 73 (34.1%) were triple negative. Conclusions: Oesophageal cancer exhibited a relatively high rate of CT antigen mRNA expression positivity.

Relationship Between Expression of MAGE-A3 with The Histopathology in NSCLC Patients

Backgrounds: Most patients with lung cancer was diagnosted in advanced stage (around 57%). Those diagnosed at early stage were only 15%. To increase the cure rate and life expectancy, lung cancer detection should be performed early. Melanoma-associated antigen 3 (MAGE-A3) is a testicular cancer antigen and is widely expressed in various types of tumor tissue. MAGE-A3 is expressed in about 35-40% of NSCLC. Previous research reported the expression of MAGE-A3 in lung cancer was 30-50%. To detect tumor antigens, CT antigens of the MAGE family can be detected through real time polymerase chain reaction (RT-PCR). This study aimed to analyze the relationship between MAGE A3 expression and histopathology type from forceps biopsy specimens in NSCLC patients. Methods: This study was a cross-sectional study conducted on 14 patients with lung cancer in September 2018 to February 2019. Subjects underwent force biopsy with guidance from bronchoscopy in the pulmonary surgery room Dr. Soetomo. The analysis used was the Fisher's exact test. Results: There were six subjects with histopathology type of adenocarcinoma (42.9%) and eight subjects (57.1%) with the histopathology of squamous cell carcinoma. Expression of MAGE-A3 was positive in 5 subjects (35.7%). Conclusions: There was no significant relationship between the expression of MAGE-A3 and the type of histopathology. (J Respir Indo. 2020; 40(2): 113-9)

Crosstalk between Stress Granules, Exosomes, Tumour Antigens, and Immune Cells: Significance for Cancer Immunity

RNA granules and exosomes produced by tumour cells under various stresses in the microenvironment act as critical determinants of cell survival by promoting angiogenesis, cancer metastasis, chemoresistance, and immunosuppression. Meanwhile, developmental cancer/testis (CT) antigens that are normally sequestered in male germ cells of the testes, but which are overexpressed in malignant tumour cells, can function as tumour antigens triggering immune responses. As CT antigens are potential vaccine candidates for use in cancer immunotherapy, they could be targeted together with crosstalk between stress granules, exosomes, and immune cells for a synergistic effect. In this review, we describe the effects of exosomes and exosomal components presented to the recipient cells under different types of stresses on immune cells and cancer progression. Furthermore, we discuss their significance for cancer immunity, as well as the outlook for their future application.

The testis protein ZNF165 is a SMAD3 cofactor that coordinates oncogenic TGFβ signaling in triple-negative breast cancer

ABSTRACTCancer/testis (CT) antigens are proteins whose expression is normally restricted to germ cells yet aberrantly activated in tumors, where their functions remain relatively cryptic. Here we report that ZNF165, a CT antigen frequently expressed in triple-negative breast cancer (TNBC), associates with SMAD3 to modulate transcription of transforming growth factor β (TGFβ)-dependent genes and thereby promote growth and survival. In addition, we identify the KRAB zinc finger protein, ZNF446, and its associated tripartite motif protein, TRIM27, as obligate components of the ZNF165-SMAD3 complex that also support tumor cell viability. Importantly, we find that TRIM27 alone is necessary for ZNF165 transcriptional activity and is required for orthotopic tumor growth in vivo. Our findings indicate that aberrant expression of a testis-specific transcription factor is sufficient to co-opt somatic transcriptional machinery to drive a pro-tumorigenic gene expression program.